Hello zl2007 and welcome to this forum. Although I'm not Publicus - he is not active anymore on this forum - but we all owe him a big "Thank you" and have the moral obligation to try to help the newcomers on this journey, which means sueing the federal government.
First of all, don't let AUSA to intimidate you. Seems to me that he is not one of the nice persons who have compassion and try to help. But you should respect him and yourself, so stay calm and professional and of course, firm on your ground. The law is on your side and with perseverence, preparation and a little luck you will prevail.
Be assured that AUSA will file something by the deadline. It is very rare (although not unheard) that AUSA files nothing by the deadline.
This can be:
1. the Answer to your complaint (in that case you don't have to file any document, the next move will come from the judge)
2. Another motion to extend. Because there was already one, the judge will be less eager to grant it, although it will greatly depend on what cause will be listed for the extension
3. AUSA will file a Motion to dismiss or remand
In this case they invariantly argue that the name check is part of the examination, which is not a single event, but rather a process, so the 120 days clock from 1447(b) didn't even start (this is based on Danilov v. Aguirre, an early victory for the Government in the Easter District of Virginia). If they prevail, the court has no subject matter jurisdiction so your case would be dismissed. This means that your first goal will be to convince the judge that examination is not a process, it is a well defined event which happened when USCIS interviewed you and that was far more than 120 days ago.
If you are successful with this, there is the other part of the motion: remand. 1447(b) leaves at the judge's discretion to either conduct a hearing and decide the matter or to remand the matter to the Service with appropriate instructions. There is very little chance that the judge will opt for the first choice. The reason for this is that no judge in this country will naturalize you without the completed full criminal background check, which contains (according to USCIS), among others, the name check, which is missing for almost all of the members of this forum. AUSA was right when he told you that there are literally many thousands of applicants with the name check pending. You still can try to argue against the remand and ask the judge that this name check should be produced during the discovery phase of the lawsuit and have a hearing to decide the matter.
Most likely the judge will simply decide the motion without a hearing and order a remand. And here comes, in my opinion, the most critical part of the whole lawsuit: to convince the judge to include in the remand order a well defined timetable. Without this, you will be back to square one, i.e., exactly where you were before your lawsuit.
If AUSA files an answer, the judge most likely will order an initial case management conference and ultimately it will be a hearing on your case.
As a general recommendation: you need to study a lot in order to be prepared to defend your case. The best place to start is the beginning of this forum. Try to read as much as you can (I read every single post, you just need lot of time and lot of patience). Take notes, save the useful info and cases posted as attachements.
Make a PACER subscription and study similar cases first in your district and after that in other jurisdictions.
Read the HANDBOOK FOR LITIGANTS WITHOUT A LAWYER - UNITED STATES DISTRICT COURT FOR THE NORTHERN DISTRICT OF CALIFORNIA (you can download it from their website. Even if you are in a different district, you can learn a ton from this well written document).
Read you court's Local Rules.
Ask questions on this forum. We are here to help each other. And good luck!
and lasted 1 hour. There were two officers. One was monitoring the camera and made copies of my green card and stuff and other was questioning.